There is currently an urgent need for compounds and/or compositions with broad-spectrum anti-bacterial activity. The increasing incidence of infectious disease caused by bacterial pathogens in both communities and hospitals is a worldwide health concern. Severe invasive infections are reported as the main complication in cancer therapies, as well as bone marrow transplantation and major surgeries. Infection is also a major concern for immuno-compromised patients with haematological malignancy and/or AIDS.
Amongst bacterial pathogens, there has recently been a significant increase of multi-drug resistance. For example, strains of Staphylococcus aureus (methicillin-resistant or MRSA) and coagulase-negative Staphylococci (CoNS) have become resistant to the most commonly used antibiotics, such that the only available antibiotics uniformly active against them are the glycopeptides, vancomycin and teicoplanin. S. aureus is one of the leading causes of hospital-acquired bacteremia capable of causing a wide range of diseases ranging from superficial skin infections to potentially fatal illnesses such as bloodstream infection, endocarditis and pneumonia (Diekema et al. Clin. Infect. Dis. 2001, 32:S114-132). Other human pathogens that have begun to develop resistance to multiple antibiotics include Streptococcus pneumoniae (the leading cause of nosocomial infections) and Pseudomonas aeruginosa, Haemophilus influenzae and Moraxella catarrhalis (the most common community-acquired respiratory pathogens; Hoban et al. Clin. Infect. Dis. 2001, 32:S81-93).
These multidrug resistant bacteria (“superbugs”) are not restricted to hospitals alone and they can be found in diverse settings including daycares, schools, prisons, sports facilities, airports, healthcare facilities, retirement homes, etc. Paper and plastics are indispensable to society and therefore need to be treated with antimicrobials to assist in the elimination of these “superbugs”.
Thus, new anti-bacterial compositions are needed to address both the growing resistance amongst microbes to present therapies and the general lack of efficacy of existing antibiotics against microorganisms.
In the cosmetics and food industry also there is a constant need for agents having antimicrobial properties, in particular for the preservation of products which are otherwise perishable, but also for direct cosmetic or therapeutic treatment of microorganisms which can have an adverse influence on the human or animal body. Reference may be made by way of example to microorganisms which can cause body odour, acne, mycoses or the like.
The antimicrobial properties of free fatty acids have been known for many years (Kabara J. et al. Antimicrobial Agents and Chemotherapy, July 1972; 2(1): pp 23-28). Bergson et al. (Antimicrobial Agents and Chemotherapy, November 2001, pp 3209-3212), reported that both capric and lauric acid were effective in killing the yeast Candida albicans. Sun et al. (Chemico-Biological Interactions 140 (2002), pp 185-198), identified the superior microbicidal properties of caprylic, capric and lauric acid, concluding that lauric was most potent against gram positive bacteria while caprylic was optimal against gram negative organisms.
WO 2011/061237 discloses antimicrobial compositions comprising free fatty acids emulsified with membrane lipids or hydrolysed derivatives thereof, and pharmaceutical formulations comprising same. The compositions can be used in the treatment or prophylaxis of microbial infections. They can also regulate the rate of blood clotting rendering them suitable for incorporation in catheter locking solutions and for use in wound care.
WO 99/51218 discloses a biocidal composition of a blend of acids substantially free of benzoic acid or a derivative thereof and comprising a mixture of lactic acid and at least one other acid selected from formic acid, acetic acid and propionic acid. In GB 1,194,863 preservative composition for crops is described comprising 70 wt. % phosphoric acid, 20 wt. % propionic acid and 5 wt. % lactic acid.
U.S. Pat. No. 7,727,568 discloses an antimicrobial composition comprising a mixture of at least 20 wt. % lactic acid or a derivative thereof and an inorganic acid selected from a nitrogen, sulfur, and phosphorous acid, and mixtures thereof for use in animal nutrition. The composition can further comprise at least one other acid selected from acetic acid, fumaric acid, gluconic acid, (iso)butyric acid, sorbic acid, (iso)valeric acid, maleic acid, malic acid, capronic acid, benzoic acid, and citric acid.
WO2014/035246 discloses antimicrobial compositions comprising at least one free fatty acid or a derivative and/or a pharmaceutically acceptable salt thereof, at least one carboxylic acid or a pharmaceutically acceptable salt thereof; and/or at least one carbohydrate or a pharmaceutically acceptable salt thereof, wherein the carbohydrate is selected from a hydrogenated carbohydrate, a monosaccharide, a disaccharide, a polysaccharide and combinations thereof. The compositions of this reference are aimed to provide an antimicrobial composition for treating or preventing the first stage in pathogenesis in order to prevent infections. This reference also discloses that a composition comprising a combination of at least one free fatty acid and at least one carboxylic acid exhibit disinfecting properties, whereas the combination of at least one free fatty acid and at least one carbohydrate, optionally in combination with at least one carboxylic acid, exerts a dual antimicrobial effect.
WO2009/140062 discloses use of amino alcohols as additives for hydrocarbonaceous compositions, such as petroleum and fuels, to improve the corrosion and microbial resistance of hydrocarbonaceous compositions. This reference also discloses that the particularly preferred amino alcohols for the desired result are 2-amino-2-methyl-1-hexanol, 2-amino-2-ethyl-1-pentanol, 2-amino-2-methyl-1-octanol, 2-amino-2-ethyl-1-heptanol, 2-amino-2-propyl-1-hexanol, (1-aminocyclohexyl)methanol, (1-aminocyclooctyl)methanol, 2-amino-2-phenyl-1-propanol, (1-aminocyclopentyl)methanol, and mixtures thereof.
There remains a need for antimicrobial compounds and/or compositions that have improved and/or broad spectrum anti-bacterial activity.
This background information is provided for the purpose of making known information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.